Tablets are usually produced by pressing a powdery material in a mould into a suitable shape in a so-called tablet-pressing machine. This process is usually referred to as tabletting. The tablets can be of different shape, size and hardness depending on the properties of the tablet material and the pressure to which they are subjected in the pressing.
When the tablets are produced, heat is generated as a result of friction against the wall surfaces of the mould and internal friction in the tablet material. Since the tablets usually consist of chemicals and the temperature increase is not particularly high, this does not cause any problem since the chemicals tolerate heat well. If, however, the tablets (the tablet material) contain living micro-organisms, such as bacteria, which are sensitive to splintering forces and heat, this leads to a severe reduction in the number of living micro-organisms, i.e. the viability, when the tablets are pressed. For certain known tablet materials, it is not uncommon for the viability in the tablet material to be reduced by up to 90%, or sometimes even more in the course of tabletting.
This problem cannot be avoided by quite simply applying a lower pressure to the conventional tablet material and thereby achieving lower heat generation, since the tablet has to be subjected to a certain minimum pressure in order for the shape to be maintainable.
A solution to this problem is, however, described by virtue of WO-A1-97/07822, which solution entails the tablet material which is pressed containing oligosaccharides, for example inulin, in addition to living micro-organisms. The pressing can consequently be effected at considerably lower pressure, resulting in reduced heat generation and increased viability.
Problem
Nevertheless, there sometimes remains the problem that the dissolution of the tablets is not always wholly satisfactory or does not occur in the ideal region. In a certain type of treatment, for example in treatment of the gastro-intestinal tract, it is vitally important for the tablets to be able to be targeted at the intended region.